Blade carts are known for use in the manufacturing process of wind turbine blades, the carts acting to support a section of the wind turbine blade towards the tip end of the blade, typically after the blade body has been molded and removed from the blade mold, and during post molding operations (e.g. external blade surface grinding or coating operations).
Current tip carts comprise an enclosed ring structure which is fitted around the body of the blade. However, as blade dimensions increase, such carts are often difficult to mount to the blade. A crane is usually needed to lift the blade tip up and down whilst the tip cart is moved (often manually) over the blade. In addition the tip cart presents an obstacle during post molding operations where people and equipment are hindered by the large ring, and prevented from easily accessing the blade leading and trailing edges at the location of the cart.
US Pat. No. 7,303,365 to Wobben discloses a support cart for a tip end of a wind turbine blade for use in long distance haulage operations. The illustrated cart is rotatable to allow for the passage of the supported blade beneath bridges and other overhanging obstacles. However, securing the blade within the cart of Wobben requires the use of bolting lugs for bolting the support cart to the blade body, and provides a mechanical coupling with the blade body such that that the cart is rotated when the root end of the blade is rotated. Such bolting lugs require additional manufacturing operations to install on the surface of the blade, and also must be subsequently removed from the blade before installation at a wind turbine to maximize aerodynamic efficiency. Furthermore, such a rigid coupling is not suitable for use with a pre-bent blade, wherein the wind turbine blade has a curved structure along the longitudinal length of the blade. Accordingly, the cart of Wobben is not suitable for use during the manufacturing process, in particular during post molding operations for a blade.
It is an object of the invention to provide a blade cart for a wind turbine blade for use during manufacturing of such a blade.